Ambrosia probably provided me the most hours of gaming entertainment over the 90s. They published Mac software and, if I remember correctly, most of their games were shareware and the non-paid versions were pretty well featured.
I wonder how many hundreds of hours I played Escape Velocity and Escape Velocity Override. Those were some absolutely amazing games and they supported plugins (mods) and had a thriving mod community.
For the 90s mac users, you’ll probably recognize a lot of their games (listed on the Wikipedia page). Here are some from the 90s that stand out to me:
Maelstrom
Chiral
Apeiron
Swoop
Barrack
Escape Velocity
Avara
Bubble Trouble
Harry the Handsome Executive
Mars Rising
EV Override
Ares
Escape Velocity Nova